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1.
Biol Lett ; 20(5): 20230595, 2024 May.
Article in English | MEDLINE | ID: mdl-38747684

ABSTRACT

The mechanisms whereby environmental experiences of parents are transmitted to their offspring to impact their behaviour and fitness are poorly understood. Previously, we showed that naive Bicyclus anynana butterfly larvae, whose parents fed on a normal plant feed but coated with a novel odour, inherited an acquired preference towards that odour, which had initially elicited avoidance in the naive parents. Here, we performed simple haemolymph transfusions from odour-fed and control-fed larvae to naive larval recipients. We found that larvae injected with haemolymph from odour-fed donors stopped avoiding the novel odour, and their naive offspring preferred the odour more, compared to the offspring of larvae injected with control haemolymph. These results indicate that factors in the haemolymph, potentially the odour molecule itself, play an important role in odour learning and preference transmission across generations. Furthermore, this mechanism of odour preference inheritance, mediated by the haemolymph, bypasses the peripheral odour-sensing mechanisms taking place in the antennae, mouthparts or legs, and may mediate food plant switching and diversification in Lepidoptera or more broadly across insects.


Subject(s)
Butterflies , Hemolymph , Larva , Odorants , Animals , Butterflies/physiology , Larva/physiology , Learning
2.
Ann N Y Acad Sci ; 1531(1): 84-94, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38113288

ABSTRACT

Many herbivorous insects have specific host-plant preferences, and it is unclear how these preferences evolved. Previously, we found that Bicyclus anynana larvae can learn to prefer novel food odors from eating leaves with those odors and transmit those learned preferences to the next generation. It is uncertain whether such acquired odor preferences can increase across generations of repeated odor feeding and be maintained even in the absence of odor. In this study, we fed larvae with novel banana odor-coated leaves (odor-fed larvae) for five consecutive generations, without selection on behavioral choices, and measured how larval innate preferences changed over time. Then, we removed the odor stimulus from a larval subgroup, while the other group continued to be odor-fed. Our results show that larvae learned to prefer the novel odor within a generation of odor feeding and transmitted the learned preference to the next generation, as previously found. Odor-fed larvae preferred odor significantly more compared to control larvae across five generations of repeated odor or control feeding. However, this led neither to increased odor preference, nor its stabilization. This suggests that when butterfly larvae feed on a new host, a preference for that novel food plant may develop and be transmitted to the next generation, but this preference lasts for a single generation and disappears once the odor stimulus is removed.


Subject(s)
Butterflies , Humans , Animals , Larva , Odorants , Plants , Herbivory , Food Preferences
3.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Article in English | MEDLINE | ID: mdl-35169073

ABSTRACT

Butterfly eyespots are beautiful novel traits with an unknown developmental origin. Here we show that eyespots likely originated via cooption of parts of an ancestral appendage gene-regulatory network (GRN) to novel locations on the wing. Using comparative transcriptome analysis, we show that eyespots cluster most closely with antennae, relative to multiple other tissues. Furthermore, three genes essential for eyespot development, Distal-less (Dll), spalt (sal), and Antennapedia (Antp), share similar regulatory connections as those observed in the antennal GRN. CRISPR knockout of cis-regulatory elements (CREs) for Dll and sal led to the loss of eyespots, antennae, legs, and also wings, demonstrating that these CREs are highly pleiotropic. We conclude that eyespots likely reused an ancient GRN for their development, a network also previously implicated in the development of antennae, legs, and wings.


Subject(s)
Body Patterning/genetics , Gene Regulatory Networks/genetics , Pigmentation/genetics , Animals , Arthropod Antennae/growth & development , Biological Evolution , Butterflies/embryology , Butterflies/genetics , Evolution, Molecular , Extremities/growth & development , Gene Expression/genetics , Gene Expression Regulation, Developmental/genetics , Phenotype , Wings, Animal/growth & development
4.
J Dev Biol ; 9(4)2021 Oct 07.
Article in English | MEDLINE | ID: mdl-34698204

ABSTRACT

The credibility of the Weismann barrier has come into question. Several studies in various animal systems, from mice to worms, have shown that novel environmental stimuli can generate an altered developmental or behavioral trait that can be transmitted to offspring of the following generation. Recently, insects have become ideal models to study the inheritance of acquired traits. This is because insects can be reared in high numbers at low cost, they have short generation times and produce abundant offspring. Numerous studies have shown that an insect can modify its phenotype in response to a novel stimulus to aid its survival, and also that this modified phenotypic trait can be inherited by its offspring. Epigenetic mechanisms are likely at play but, most studies do not address the mechanisms that underlie the inheritance of acquired traits in insects. Here we first review general epigenetic mechanisms such as DNA methylation, histone acetylation and small noncoding RNAs that have been implicated in the transmission of acquired traits in animals, then we focus on the few insect studies in which these mechanisms have been investigated.

5.
Proc Biol Sci ; 288(1951): 20202840, 2021 05 26.
Article in English | MEDLINE | ID: mdl-34034526

ABSTRACT

There are fewer eyespots on the forewings versus hindwings of nymphalids but the reasons for this uneven distribution remain unclear. One possibility is that, in many butterflies, the hindwing covers part of the ventral forewing at rest and there are fewer forewing sectors to display eyespots (covered eyespots are not continuously visible and are less likely to be under positive selection). A second explanation is that having fewer forewing eyespots confers a selective advantage against predators. We analysed wing overlap at rest in 275 nymphalid species with eyespots and found that many have exposed forewing sectors without eyespots: i.e. wing overlap does not constrain the forewing from having the same number or more eyespots than the hindwing. We performed two predation experiments with mantids to compare the relative fitness of and attack damage patterns on two forms of Bicyclus anynana butterflies, both with seven hindwing eyespots, but with two (in wild-type) or four (in Spotty) ventral forewing eyespots. Spotty experienced more intense predation on the forewings, were shorter-lived and laid fewer eggs. These results suggest that predation pressure limits forewing eyespot number in B. anynana. This may occur if attacks on forewing eyespots have more detrimental consequences for flight than attacks on hindwing eyespots.


Subject(s)
Butterflies , Animals , Pigmentation , Predatory Behavior , Wings, Animal
6.
Evolution ; 73(12): 2401-2414, 2019 12.
Article in English | MEDLINE | ID: mdl-31598962

ABSTRACT

Many phytophagous insects have strong preferences for their host plants, which they recognize via odors, making it unclear how novel host preferences develop in the course of insect diversification. Insects may learn to prefer new host plants via exposure to their odors and pass this learned preference to their offspring. We tested this hypothesis by examining larval odor preferences before and after feeding them with leaves coated with control and novel odors and by examining odor preferences again in their offspring. Larvae of the parental generation developed a preference for two of these odors over their development. These odor preferences were also transmitted to the next generation. Offspring of butterflies fed on these new odors chose these odors more often than offspring of butterflies fed on control leaves. In addition, offspring of butterflies fed on banana odors had a significant naïve preference for the banana odors in contrast to the naïve preference for control leaves shown by individuals of the parental generation. Thus, butterflies can learn to prefer novel host plant odors via exposure to them during larval development and transmit these learned preferences to their offspring. This ability potentially facilitates shifts in host plant use over the course of insect diversification.


Subject(s)
Butterflies/genetics , Butterflies/physiology , Learning , Odorants , Plants/chemistry , Animals , Diet , Feeding Behavior , Female , Larva , Oviposition , Plant Leaves
7.
Asian Pac J Cancer Prev ; 19(11): 3093-3098, 2018 Nov 29.
Article in English | MEDLINE | ID: mdl-30486547

ABSTRACT

This paper addresses the automated detection of microcalcification clusters from mammogram images by enhanced preprocessing operations on digital mammograms for automated extraction of breast tissue from background, removing artefacts occurring during image registration using X-rays, followed by fractal analysis of suspicious regions. Identification of breast of either left or right and realigning them to a standard position forms a primitive step in preprocessing of mammograms. As the next step in the process, pectoral muscles are separated. Suspicious regions of microcalcifications are identified and are subjected to further analysis of classifying it as benign or malignant. Texture features are representative of its malignancy and fractal analysis was carried out on extracted suspicious regions for its texture features. Principal Component Analysis was carried out to extract optimal features. Ten features were found to be an optimal number of reduced texture features without compromising on classification accuracy. Scaled conjugate Gradient Back propagation network was used for classification using reduced texture features obtained from PCA analysis. By varying hidden layer neurons, accuracy of results achieved by proposed methods is analysed and is calculated to reach maximum accuracy with an optimal level of 15 neurons. Accuracy of 96.3% was achieved with 10 fractal features as input to neural network and 15 hidden layer neurons in neural network designed. The design of architecture is finalised with maximised accuracy for labelling microcalcification clusters as benign or malignant.


Subject(s)
Breast Neoplasms/complications , Breast/pathology , Calcinosis/classification , Calcinosis/pathology , Fractals , Mammography/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Algorithms , Automation , Breast Neoplasms/pathology , Calcinosis/etiology , Female , Humans , Prognosis
8.
Eur J Obstet Gynecol Reprod Biol ; 215: 230-233, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28683376

ABSTRACT

OBJECTIVE: To validate whether change in serum HCG levels between days 0 and 4 confer any prognostic value during methotrexate therapy and to quantify its change. STUDY DESIGN: This is a retrospective study of 48 tubal ectopic pregnancies treated with single dose methotrexate protocol at University Hospital, Muscat, Oman from January 2012 to December 2013. The clinical outcome was analyzed based on the complete resolution of HCG levels or need for additional doses of methotrexate or recourse to surgery. The percentage change in HCG levels between days 0 and 4 (HCG index) of methotrexate were calculated and receiver operator characteristics curve was plotted to identify the best cutoff levels. In order to get a robust 95% confidence interval, bootstrap method using R software was done using 1000 re-sampling. ROC curve and the predictive values were estimated using MEDCALC software. RESULTS: The mean HCG level on day 4 is significantly higher in treatment failure group (4254±4095 IU/L vs. 2109±3646 IU/L, P=0.008). The HCG levels between day 0 and 4 decreased in 42.7% (21/48) of cases and 80.9% of these cases had treatment success. The HCG levels increased in 57.4% (27/48) of cases and 33.3% of these cases had treatment success. (P=0.001). A 10 percent decline in day 4 HCG levels predict the treatment success with sensitivity of 77% and Specificity 81%. The area under the ROC curve was 0.82 (95% CI: 0.67-0.92), (P<0.001). CONCLUSION: The success with single dose of methotrexate therapy for tubal ectopic pregnancies was predicted early in the course of treatment by following three key findings: the absolute mean HCG values on day 4, decrease in HCG level from day 0 to 4 and 10% or more fall in day 4 HCG levels.


Subject(s)
Abortifacient Agents, Nonsteroidal/therapeutic use , Chorionic Gonadotropin/blood , Methotrexate/therapeutic use , Pregnancy, Ectopic/drug therapy , Adult , Female , Humans , Pregnancy , Pregnancy, Ectopic/blood , Prognosis , Retrospective Studies , Treatment Outcome , Young Adult
9.
Technol Health Care ; 25(4): 641-649, 2017 Aug 09.
Article in English | MEDLINE | ID: mdl-28436399

ABSTRACT

BACKGROUND: The spectral analysis of the heart rate variability (HRV) shows a decrease in the power of the high frequency (HF) component in preeclamptic pregnancy compared with normal pregnancy; such a decrease is associated with an increase in the low frequency (LF) and the very low frequency (VLF) power. The physiological interpretation is that preeclamptic pregnancy is associated with a facilitation of sympathetic regulation and an attenuation of parasympathetic influence of HR compared with non-pregnancy and normal pregnancy. OBJECTIVE: To use an efficient nased on spectral analysis non-invasive technique to identify preeclamptic pregnant subjects from normal pregnant in Oman. METHODS: The soft-decision wavelet-based technique is implemented to find the power of the HRV bands in high resolution manner compared to the classical fast Fourier Transform method. Data was obtained from 20 preeclamptic pregnant subjects and 20 normal pregnant controls of the same pregnancy duration, obtained from Nizwa and Sultan Qaboos University hospitals in Oman. RESULTS: The soft-decision wavelet method succeeds to identify patients from normal pregnant with specificity, sensitivity and accuracy of 90%, 80% and 85%, respectively, compared to the FFT which results in 75% specificity, sensitivity and accuracy. CONCLUSION: The LF power obtained by Soft-decision wavelet decomposition is shown to be a successful feature for identification of preeclampsia.


Subject(s)
Heart Rate/physiology , Pre-Eclampsia/diagnosis , Pre-Eclampsia/physiopathology , Wavelet Analysis , Adult , Algorithms , Female , Fourier Analysis , Humans , Oman , Pregnancy , Sensitivity and Specificity
10.
Mol Biochem Parasitol ; 195(1): 14-22, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24893338

ABSTRACT

The protozoan parasite Cryptosporidium parvum causes severe enteric infection and diarrheal disease with substantial morbidity and mortality in untreated AIDS patients and children in developing or resource-limited countries. No fully effective treatment is available. Hypusination of eIF5A is an important post-translational modification essential for cell proliferation. This modification occurs in a two step process catalyzed by deoxyhypusine synthase (DHS) followed by deoxyhypusine hydroxylase. An ORF of 1086bp was identified in the C. parvum (Cp) genome which encodes for a putative polypeptide of 362 amino acids. The recombinant CpDHS protein was purified to homogeneity and used to probe the enzyme's mechanism, structure, and inhibition profile in a series of kinetic experiments. Sequence analysis and structural modeling of CpDHS were performed to probe differences with respect to the DHS of other species. Unlike Leishmania, Trypanosomes and Entamoeba, Cryptosporidium contains only a single gene for DHS. Phylogenetic analysis shows that CpDHS is more closely related to apicomplexan DHS than kinetoplastid DHS. Important residues that are essential for the functioning of the enzyme including NAD(+) binding residues, spermidine binding residues and the active site lysine are conserved between CpDHS and human DHS. N(1)-guanyl-1,7-diaminoheptane (GC7), a potent inhibitor of DHS caused an effective inhibition of infection and growth of C. parvum in HCT-8 cells.


Subject(s)
Cryptosporidiosis/parasitology , Cryptosporidium parvum/metabolism , Lysine/analogs & derivatives , Biosynthetic Pathways , Cryptosporidium parvum/genetics , Humans , Lysine/biosynthesis , Models, Molecular , Molecular Sequence Data , Phylogeny , Protozoan Proteins/genetics , Protozoan Proteins/metabolism
11.
Ann Med Health Sci Res ; 4(2): 286-8, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24761256

ABSTRACT

BACKGROUND: Abdominal pain is one of the most common presentations of adnexal pathology in gynecology. Early diagnosis and intervention is essential especially in adolescent girls and reproductive age group women to conserve reproductive function. AIM: The purpose of the following study is to assess the clinicopathologic outcome of women with adnexal masses presenting with acute pain. SUBJECTS AND METHODS: A retrospective study of women with adnexal masses who had surgical intervention for acute symptoms from June 2007 to May 2012 was undertaken. During the study period, a total of 57 women were operated for adnexal masses as emergency. RESULTS: Of the 57 women operated for adnexal masses as emergency, the most common pathology was teratoma 26% (15/57) followed by corpus luteal hemorrhage (16%) and endometriosis (14%). Laparoscopy was the initial surgical approach in just over 50% of patients, but surgery was completed laparoscopically only in about one-third of patients. Conservative surgery in the form of ovarian cystectomy was possible in 70% of patients. CONCLUSION: Complications of adnexal masses such as torsion and hemorrhage are common causes of acute abdominal pain. Timely diagnosis of the adnexal pathology and surgical intervention will help to preserve the reproductive outcome. Conservative surgery was possible in 70% of our study group.

12.
Transfusion ; 54(1): 238-43, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23829228

ABSTRACT

BACKGROUND: The management of pregnant women with anti-Jsb is challenging due to the paucity of antigen-negative blood for fetal and neonatal transfusion. CASE REPORT: A 29-year-old woman with anti-Jsb was referred for assessment of recurrent fetal losses. With the presence of the sister as a historically matched donor, she was planned for active surveillance for fetal anemia during pregnancy. STUDY DESIGN AND METHODS: The fetus remained well until 21 weeks of gestation when signs of fetal anemia and early hydrops fetalis were noted. Anti-Jsb titer was at 128. The sister's red blood cells (RBCs) were cross-match incompatible. Urgent intrauterine transfusion (IUT) was performed with washed irradiated maternal RBCs, donated after cessation of heparin. The mother was given intravenous iron (IV-Fe) and continued on weekly recombinant human erythropoietin (rHu-EPO). RESULTS: Repeated IUTs were needed every 1 to 3 weeks. Throughout a 7-week period, three maternal donations were performed with total donated whole blood volume of 1250 mL, supporting four IUTs. At 29 weeks of gestation, the procedure was complicated by umbilical cord hematoma necessitating urgent cesarean section. A male newborn was delivered, transfused at birth, and subsequently treated with phototherapy and five top-up transfusions. CONCLUSION: This case represents a successful example of managing hemolytic disease of the fetus due to a rare antibody using maternal blood. It also supports previous data on safety of maternal donations during pregnancy and the use of combination of rHu-EPO and IV-Fe as a supportive measure.


Subject(s)
Blood Transfusion, Intrauterine/methods , Erythroblastosis, Fetal/therapy , Isoantibodies/adverse effects , Kell Blood-Group System/immunology , Adult , Blood Donors , Erythroblastosis, Fetal/etiology , Female , Humans , Infant, Newborn , Isoantibodies/blood , Male , Mothers , Pregnancy , Severity of Illness Index , Treatment Outcome
13.
Oman Med J ; 28(4): 292-3, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23904927
14.
BMC Genomics ; 13: 621, 2012 Nov 14.
Article in English | MEDLINE | ID: mdl-23151081

ABSTRACT

BACKGROUND: Leishmania major, a protozoan parasite, is the causative agent of cutaneous leishmaniasis. Due to the development of resistance against the currently available anti-leishmanial drugs, there is a growing need for specific inhibitors and novel drug targets. In this regards, aminoacyl tRNA synthetases, the linchpins of protein synthesis, have received recent attention among the kinetoplastid research community. This is the first comprehensive survey of the aminoacyl tRNA synthetases, their paralogs and other associated proteins from L. major. RESULTS: A total of 26 aminoacyl tRNA synthetases were identified using various computational and bioinformatics tools. Phylogenetic analysis and domain architectures of the L. major aminoacyl tRNA synthetases suggest a probable archaeal/eukaryotic origin. Presence of additional domains or N- or C-terminal extensions in 11 aminoacyl tRNA synthetases from L. major suggests possibilities such as additional tRNA binding or oligomerization or editing activity. Five freestanding editing domains were identified in L. major. Domain assignment revealed a novel asparagine tRNA synthetase paralog, asparagine synthetase A which has been so far reported from prokaryotes and archaea. CONCLUSIONS: A comprehensive bioinformatic analysis revealed 26 aminoacyl tRNA synthetases and five freestanding editing domains in L. major. Identification of two EMAP (endothelial monocyte-activating polypeptide) II-like proteins similar to human EMAP II-like proteins suggests their participation in multisynthetase complex formation. While the phylogeny of tRNA synthetases suggests a probable archaeal/eukaryotic origin, phylogeny of asparagine synthetase A strongly suggests a bacterial origin. The unique features identified in this work provide rationale for designing inhibitors against parasite aminoacyl tRNA synthetases and their paralogs.


Subject(s)
Amino Acyl-tRNA Synthetases/genetics , Archaeal Proteins/genetics , Bacterial Proteins/genetics , Computational Biology , Leishmania major/genetics , Protozoan Proteins/genetics , Amino Acid Sequence , Amino Acyl-tRNA Synthetases/classification , Asparagine/genetics , Asparagine/metabolism , Cytokines/genetics , Cytokines/metabolism , Evolution, Molecular , Leishmania major/enzymology , Models, Molecular , Molecular Sequence Data , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Phylogeny , Protein Multimerization , Protein Structure, Tertiary , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Sequence Alignment , Sequence Homology, Amino Acid
16.
Phys Chem Chem Phys ; 13(12): 5383-7, 2011 Mar 28.
Article in English | MEDLINE | ID: mdl-21340085

ABSTRACT

The simplicity and analytical utility of silver nanoparticles used as immunolabels with screen-printed measurement electrodes is illustrated by demonstrating an appropriate analytical signal for myoglobin (a protein marker for muscle damage) across a range of concentrations of physiological interest for distinguishing potential myocardial infarctions from normal background levels in serum. Silver nanoparticles were used as labels on one of a pair of anti-myoglobin clones while the other clone was covalently attached to magnetic beads. The two clones were selected so as to bind to different sites on the target protein and allow the formation of complexes containing both magnetic beads and silver nanoparticles. The magnetic beads enabled protein captured from test samples to be separated from other components, while the silver nanoparticles enabled the protein to be quantified. An oxidising potential, applied to screen-printed carbon electrodes, was used to dissolve silver without the need for an external oxidising agent. Silver ions released in the process were subsequently accumulated at the measurement electrodes by applying a suitable reducing potential and, finally, analytical signals were obtained by integrating the charges passed when accumulated silver was stripped from the electrodes by applying a potential ramp. The magnitudes of the measured charges were indicative of the concentrations of myoglobin in each of the test solutions.


Subject(s)
Magnetics , Nanoparticles/chemistry , Silver/chemistry , Animals , Electrochemistry , Immunoassay/instrumentation , Myoglobin/analysis , Myoglobin/chemistry
17.
Int J Biol Macromol ; 48(2): 276-85, 2011 Mar 01.
Article in English | MEDLINE | ID: mdl-21126533

ABSTRACT

The present study describes preparation and characterization of a thermally stable and biodegradable biopolymer using collagen and a natural polymer, alginic acid (AA). Required concentration of alginic acid and collagen was optimized and the resulting biopolymer was characterized for, degree of cross-linking, mechanical strength, thermal stability, biocompatibility (toxicity) and biodegradability. Results reveal, the degree of cross-linking of alginic acid (at 1.5% concentration) with collagen was calculated as 75%, whereas it was 83% with standard cross-linking agent, glutaraldehyde (at 1.5% concentration). The AA cross-linked biopolymer was stable up to 245°C and Exhibits 5-6-fold increase in mechanical (tensile) strength compared to plain collagen (native) materials. However, glutaraldehyde cross-linked material exhibits comparatively less thermal stability and brittle in nature (low tensile strength). With regard to cell toxicity, no cytotoxicity was observed for AA cross-linked material when tested with mesenchymal cells and found degradable when treated with collagenase enzyme. The nature of bonding pattern and the reason for thermal stability of AA cross-linked collagen biopolymer was discussed in detail with the help of bioinformatics. A supplementary file on efficacy of AACC as a wound dressing material is demonstrated in detail with animal model studies.


Subject(s)
Biopolymers/chemistry , Cross-Linking Reagents/chemistry , Temperature , Alginates/chemistry , Animals , Biodegradation, Environmental , Calorimetry, Differential Scanning , Cattle , Collagen/chemistry , Collagen/ultrastructure , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Hydrogen Bonding , Hydroxyproline/metabolism , Mesenchymal Stem Cells/cytology , Models, Molecular , Solubility , Tensile Strength , Thermogravimetry
18.
JNMA J Nepal Med Assoc ; 51(184): 196-8, 2011.
Article in English | MEDLINE | ID: mdl-22922901

ABSTRACT

With the rising incidence of caesarean sections, the number of cases of placenta praevia and morbidly adherent placenta is increasing. Antenatal diagnosis and management in a tertiary care centre helps to reduce maternal and neonatal morbidity and mortality. We present a patient in whom the antenatal diagnosis of morbidly adherent placenta was missed due to late booking. In spite of the conservative approach at the time of caesarean section in the secondary care hospital, the patient presented with delayed complications and a total hysterectomy was performed.


Subject(s)
Cesarean Section/adverse effects , Hysterectomy/methods , Placenta Accreta/diagnosis , Postpartum Hemorrhage/etiology , Prenatal Diagnosis , Adult , Diagnosis, Differential , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Placenta Accreta/surgery , Postpartum Hemorrhage/diagnosis , Postpartum Hemorrhage/surgery , Pregnancy
19.
Gene ; 429(1-2): 1-9, 2009 Jan 15.
Article in English | MEDLINE | ID: mdl-18983902

ABSTRACT

Methylglyoxal is mainly catabolized by two major enzymatic pathways. The first is the ubiquitous detoxification pathway, the glyoxalase pathway. In addition to the glyoxalase pathway, aldose reductase pathway also plays a crucial role in lowering the levels of methylglyoxal. The gene encoding aldose reductase (ALR) has been cloned from Leishmania donovani, a protozoan parasite causing visceral leishmaniasis. DNA sequence analysis revealed an open reading frame (ORF) of approximately 855 bp encoding a putative protein of 284 amino acids with a calculated molecular mass of 31.7 kDa and a predicted isoelectric point of 5.85. The sequence identity between L. donovani ALR (LdALR) and mammals and plants is only 36-44%. The ORF is a single copy gene. A protein with a molecular mass that matched the estimated approximately 74 kDa according to the amino acid composition of LdALR with a maltose binding tag present at its N-terminal end was induced by heterologous expression of LdALR in Escherichia coli. In the presence of glutathione, recombinant LdALR reduced methylglyoxal with a K(m) of approximately 112 microM. Comparative structural analysis of the human ALR structure with LdALR model suggests that the active site anchoring the N-terminal end of the glutathione is highly conserved. However, the C-terminal end of the glutathione backbone is expected to be exposed in LdALR, as the residues anchoring the C-terminal end of the glutathione backbone come from the three loop regions in human, which are apparently shortened in the LdALR structure. Thus, the computational analysis provides clues about the expected mode of glutathione binding and its interactions with the protein. This is the first report of the role of an ALR in the metabolic disposal of methylglyoxal in L. donovani and of thiol binding to a kinetoplastid aldose reductase.


Subject(s)
Aldehyde Reductase/metabolism , Glutathione/metabolism , Inactivation, Metabolic , Leishmania donovani/enzymology , Pyruvaldehyde/metabolism , Aldehyde Reductase/chemistry , Aldehyde Reductase/isolation & purification , Amino Acid Sequence , Animals , Biocatalysis , Blotting, Southern , Escherichia coli , Genome, Protozoan/genetics , Humans , Kinetics , Leishmania donovani/genetics , Models, Molecular , Molecular Sequence Data , Phylogeny , Sequence Alignment , Substrate Specificity
20.
Anal Chim Acta ; 614(2): 190-5, 2008 May 05.
Article in English | MEDLINE | ID: mdl-18420050

ABSTRACT

A simple and sensitive liquid chromatographic method has been developed for the determination of low molecular weight aliphatic amines after their pre-column derivatization with naphthalene-2,3-dicarboxaldehyde (NDA). Derivatization conditions, including the NDA concentration, reaction pH and reaction time have been investigated for method optimization. The chromatographic separation of five amines was performed on ABZ PLUS column using mobile phase of methanol-water (80:20, v/v) at a flow rate of 0.2 mL min(-1). The detection was carried out with a 6 mm glassy carbon electrode at the applied potential of 0.7 V versus Ag/AgCl reference electrode. The detection limits were between 23.3 and 34.4 nmol L(-1) of amines with a sample injection volume of 2 microL. The present method was applied for the determination of aliphatic amines in lake water. The recovery ranged 52.2-127.9%. The RSD in analytes retention time was less than 0.3% and 2.4% for intra- and inter-day analyses, respectively. The RSD in peak area was below 5.8% for both intra-day and inter-day analyses. The total analysis was completed within 20 min.


Subject(s)
Amines/analysis , Naphthalenes/chemistry , Calibration , Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Electrochemistry/instrumentation , Electrochemistry/methods , Fresh Water/chemistry , Hydrogen-Ion Concentration , Molecular Weight , Reproducibility of Results , Sensitivity and Specificity , Time Factors , Water Pollutants, Chemical/analysis
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